This invention relates in general to an internetwork replica routing system and more particularly relates to a system for directing a client computer to a server replica that is estimated to provide good performance for the client computer.
The recent rapid growth of users of international public packet-switched computer internetworks such as the Internet has created a large demand for the information and services they contain. The replication of services in an internetwork makes it possible for such services to service many users.
Certain known approaches for automatically directing client computers to servers include, for example, round robin DNS and loading balancing DNS, which direct users to one of a number of server replicas in an attempt to balance the load among many servers. In another approach called multiple hostnames, content is spread over multiple servers, each with a separate hostname. Web pages returned to users contain links that point at the replica that has been selected for the user based on load-balancing concerns and replica content considerations. In another approach called Internet load balancing, a hardware component automatically distributes user requests sent to a single IP address to one of a number of server replicas to implement load balancing. Another approach is resonate dispatch that combines load balancing with replica capability to automatically direct users to a replica that is operational, is not overloaded with requests, and contains the requested information.